• Radiosonde - A.I.R. Inc. Airsonde

A small radio transmitter, carried upwards by a balloon, by means of which measurements of pressure, temperature and humidity may be obtained from the upper atmosphere. Model AS-TH. SN8103260015, carrier frequency MHZ 403.497. Patent number 4,112,753, granted on 12th September 1978.

The temperature sensor was mounted in a tube at the end of one of the blades with the humidity sensor in the opposite tube. Also recorded wind velocity data. Propeller construction designed so that the radiosonde would spin whilst in flight, allowing continuous airflow to the sensors to provide more accurate readings. Intended to ascend with the blades at the base and then rotate once the balloon burst with the propellers facilitating a controlled descent, removing the need for a parachute.